Pattern of spine degenerative disease among patients referred for lumbar magnetic resonance imaging at Muhimbili National Hospital, Dar es salaam, Tanzania March-September-2010.

Abstract

Abstract Background Degenerative disease of the lumbar spine refers to a syndrome in which an intervertebral disk with adjacent spine structures are compromised. This causes low back and lower extremity pain. The syndromes encompasses the following degenerative changes:.disk degeneration, Modic changes, disk displacement, nerve root compression, facet joints arthropathy, ligamentum flavum hypertrophy and spine canal stenosis. The modality of choice for imaging this syndrome is Magnetic Resonance Imaging (MRI). Objective: Assessment of pattern of lumbar spine degenerative disease among patients with with/without radiculopathy, referred for lumbar MRI at Muhimbili National Hospital(MNH) from March-September 2010. Methodology: This descriptive cross-sectional study involved 165 individuals selected from patients referred for lumbar MRI at MNH. A questionnaire was administered to obtain patient demographic data and clinical information. In all participants, lumbar MRI scans were performed through L1-S1 intervertebral disc spaces. Six degenerative findings were looked at: (i) disk degeneration (ii) Modic changes (iii)disk bulge (iv) disk herniation (v)central canal stenosis (vi)nerve root compression. Statistical analysis was performed using computer program Statistical Package for Social Sciences (SPSS) version; 13. Chi-square test was, used to compare between age, gender, symptomatology and MRI findings. A p-value of <0.05 was considered to indicate statistically significant difference. Results The mean age of participants was 50±12.5 years. Eighty percent (80%) of participants presented with LBP with radiculopathy. After lumbar MRI, 93.9% of participants had at least one degenerative finding. Disk degeneration was found in 83% of individuals, in at least one intervertebral disc level, Modic changes (28%), disc bulging (39%), disc protrusion (63%), vi central canal stenosis (30%) and nerve root compression (77%) were detected. Type II Modic changes were more common than type I (22% and 6% respectively: p-value: 0.022). Ninty eight percent of herniated disks were protrusions. Two percent of herniated disks were extrusions and the most location for disk herniation was postero-lateral seen in 75% of herniated disks. None of the participants had disk sequestration. The degenerative imaging findings were increasing significantly with age and there was no significant sex difference. All degenerative findings were seen at lower lumbar levels (L4/L5&L5/S1) but were more common at the L4/L5. Disk herniations, central canal stenosis and nerve root compression were common in patients with radiculopathy than in patients with LBP only (p-value 0.000). Conclusion Majority (93.9%) of participants had at least one degenerative imaging finding. The most frequent degenerative finding was disk degeneration(83%). Posterolateral was the most common location for disk herniation. Disk herniation, canal stenosis and nerve root compression were significantly seen in patients with radiculopathy. There were no sequestered disks found in the studied patients. Recommendations 1) MR axial images should be obtained in a contiguous manner 2) Careful evaluation of images is needed as different types of lumbar spine degenerative findings are common among patients referred for Lumbar MRI 3) There is a need of more studies to be conducted on spine degenerative disease using bigger sample sizes